This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. : High quality structure determination of RNA molecules using NMR spectroscopy became a wire area of interest in recent past. Tertiary structure of RNA relay on the base pair formation between the nucleic acids. The labile protons those are involving in the base pair formation are exchange with water at ambient temperatures. We propose to determine the tertiary structure of RNA at sub zero possibly at -17C temperatures using the supercooled water techniques. At that temperature we possibly observe the exchangeable protons such as imino, sugar hydroxyls that will help giving more conformational distance restrains to derive high quality RNA structure. We selected U6ISL RNA to study the supercooled water. For this study we are going to use the RT probe to reach the sample temperature to -17C.